The present invention is directed to a solenoid actuated valve device and more particularly to a solenoid actuated valve device for controlling the flow of fluid in proportion to the electric current energizing the solenoid.
A conventional solenoid actuated valve device is comprised of a linear motor of the movable coil type, a valve means and spring means normally biasing the valve means to the closed position. The linear motor includes a core, a bobbin slidably mounted on the core, a solenoid coil wound on the bobbin, permanent magnets mounted adjacent the solenoid coil so that the magnetic flux of each magnet intersects the winding of the solenoid coil at right angles thereto and a yoke or body forming a magnetic circuit with the core. The valve means in general includes a sliding valve member which slides with the bobbin on the core against the biasing force of the spring means in response to an electric current flowing through the solenoid coil to thereby proportionally control the opening and closing of apertures formed in the core between an inlet port and an outlet port.
The U.S. Pat. No. 4,286,767 to Hashimoto granted Sept. 1, 1981, the U.S. Pat. No. 4,216,938 to Inada et al granted Aug. 12, 1980 and U.S. patent application Ser. No. 105,438 filed Dec. 19, 1979 in the name of Inada et al are examples of such solenoid actuated valve devices. The foregoing application and patents are each assigned to the same assignee as the present application.
In such prior solenoid actuated valves, the valve means are returned to their original closed position by the biasing force of the spring means. Since the electric current to the solenoid is interrupted abruptly the spring means will return the valve quickly so that the end of the valve means will hit against a stopper which is generally formed integrally with the body with a considerable amount of force. In addition to the undesirable noise created by such a condition, the constant banging of the valve means against the stopper tends to affect the reliability and long life of the solenoid actuated valve.